A Bad Side of Good Cancer Treatments May Hold Clues for Resistance

Monday, August 10, 2015

A paradox of cancer therapy is that sometimes treatment can make the disease worse. A Roswell Park Comprehensive Cancer Center scientist has published a review in the journal Cancer Research that explains this phenomenon in animal studies and details examples of when treatment helped cancer metastases spread and grow.

“Starting more than 60 years ago, studies in animals suggested that under certain circumstances, cancer treatments such as surgery, radiation, and chemotherapy can create conditions that help cancer spread, often while simultaneously blocking cancer growth,” says John Ebos, PhD, Assistant Professor of Oncology, Departments of Cancer Genetics and Medicine at Roswell Park. “This area of research is surprisingly broad and detailed, though it is mostly overlooked.”

Understanding these mechanisms may hold clues as to why the benefits of certain cancer treatments in humans are often more limited than preclinical models predict. “A broader exploration of this phenomenon may help explain treatment failure and provide clues on how to improve patient treatment outcomes,” says Dr. Ebos.

Key points of the review article are:

Under certain specific experimental conditions in animals, cancer treatments have been shown to help metastases grow.

This effect is broad and extensive and it is possible that therapies have common underlying mechanisms, many of which may provide targets for future anti-metastatic treatments to improve outcomes in patients.

Understanding how host responses to therapies targeting the tumor microenvironment can influence metastasis is currently an active area of study in Dr. Ebos’ laboratory.